This invention relates to a reel-to-reel drive system and particularly such apparatus adapted for transfer of a film strip between two spaced reels.
Information is conveniently stored on film to provide compact storage means. For example, hundreds of normal sized pages may be stored on a single 3.times.5 film fiche sheet, commonly identified as a microfiche or more recently a higher density card ultrafiche. A simple card file may therefore store a substantial library of information and books with convenient and ready access thereto. A special optical reader is provided for enlargement of any given page stored on any given card. A hard copy of the enlarged material is conveniently provided by providing the reader with a printer. For example, the inventor's issued U.S. Pat. No. 4,322,158 which issued Mar. 30, 1982 entitled "Thermal Film Developing Apparatus" discloses a reader-printer apparatus for microfiche cards or the like.
In addition to the fiche cards, photographic film rolls, usually in the form of a reel, a cartridge or a cassette, are widely used. In such a storage medium, multiframe film strip is wound on a reel with successive film frames carrying the reduced images. The film roll is housed on a reel which may be suitably mounted within a suitable cassette or cartridge. A film reader includes a suitable optical enlargement means for enlarging of the material on a film frame and displaying thereof on viewing screen. The cartridge that is releasably held in place and a film drive is coupled to the film reel and includes means to automatically withdraw the end of the strip from the cartridge and pass it into and through the projection unit to a take-up reel on the opposite side of the projection unit. The take-up reel is coupled to a multiple speed drive system to be separately driven in such a direction as to wind the film from the cassette onto the reel. The cartridge unit is also adapted to be reversely driven to rewind the film strip. This permits the user to rapidly transfer the film strip through the projection unit for aligning of the desired frame of the film strip in the projection unit. As in the fiche reader, a printer is advantageously associated with the reader for production of a hard copy of any given frame of the projected material.
A microfiche reader and/or printer reader is normally manually loaded and unloaded and does not have the requirement of the cartridge drive system. However, many users may have both a microfiche storage and/or film cassette storage. A single printer-reader which is adapted to both microfiche and film strip would be desirable to minimize and simplify manufacture and inventory requirements as well as to minimize equipment cost of the end user. Thus, form a manufacturing standpoint, the inventors have recognized the advantage of a single printer-reader in combination with separate adaptors for fiche systems and for film strip reel systems. The purchaser can be offered a basic printer-reader with either or both of the adaptors in order to match the system capability to the system used.
Such adapted systems are available, but the drive systems are relatively complex and costly. Various such dual systems have been developed, for example, using a single motor with suitable couplings for driving the cartridge and the take-up reel.
In a film strip system, the drivers uniformly provide for dual speed movement including a rapid transfer mode to permit movement of the film to the desired frame area in a rapid manner. A slower speed drive mode is also permitted for accurate location of a given frame. The shifting system must therefore include various clutchings and gear systems to permit both rapid and slow speeds in both of selective forward and reverse drive connections. The control is preferably constructed with a single unit control, such as a rotary dial. The mechanical shifting mechanisms to control the transfer of the film strip may be relatively complex and therefor costly to construct and to maintain.
There is a need for an improved reversible, multiple speed drive system for reel-to-reel applications and particularly in the information storage art. Although particularly applicable to film storage systems, other data systems which use other elongated elements for information storage may present similar problems of rapid access and accurate location, and the present invention may of course be applied to such other fields. The drive system should have a long operating life in view of the substantial usage and the importance of the application. However, the system must have significant cost effectiveness in order to replace the conventional hard copy storage.